1. Field of the Invention
This invention relates to methods of encoding digital data into binary form, and decoding such binary data. The binary system, using 1's (ones) and 0's (zeroes) to represent alphanumeric data, is well known in the art. Currently, two types of binary code are used most commonly: the Baudot code, a five-hole code for representing alphanumeric characters; and the binary coded decimal (BCD) code, used to represent decimal numbers in binary form.
From the binary system's inception, the number of bits available for encoding was often less than the number of bits required to represent a letter or number. The original five-hole Baudot code, for example, permitted only 32 unique combinations, insufficient to represent the entire 26-character English alphabet in both upper case and lower case form. The BCD code, in which any decimal number can be represented in binary form, requires a great many digits to represent numbers. For example, four digits, or "bits" are needed to represent the decimal number 8.
Historically, solutions to this problem have been attempted in two categories: expanding the capacity of the encoding medium, or modifying the code interpreting system. When the size of the system that includes this coding method is inflexibly determined due to cost considerations or physical limitations, only the latter category of solutions is viable.